Variable-speed friction gear



y 1951' J. J. VAN LEEUWEN 2,552,751

' VARIABLE-SPEED FRICTION GEAR Filed Oct; 14, 1948 v 2 Sheets-Sheet 1 r I r E F nae a- F? H 6 r 12" F 15 J g FIZZ/v GJUZILZ y 15, 1951 J. J. VAN LEEUWEN 2,552,751

VARIABLE-SPEED FRICTION GEAR Filed Oct. 14, 1948 2 Sheets-Sheet 2 FlG.9.

Patented May 15 1951 UNITED STATES PATENT OFFICE FRICTION GEAR Jacobus J oannes van Leeuwen, Amsterdam,

' Netherlands Application October 14, 1948, Serial No. 54,447 i nu sahel meme 94 friction gearsare already known. Ina known construction of'ft his kind the two friction wheels are mounted on" a "common spindle and" are thus coupled for rotation in the same sense. For obtaining a compensation of the'forces actmg on the set of friction wheels, insuch a construction the friction wheels must be large and the common spindle of'the set has to make a sharp angle with the direction of the two spindlesiof the main gear discs. This causes inevitably that the friction whens lie against theinain gearfdiscs with relatively'large surfaces, while the touching plates offthe 'two friction wheelswith the mainl'g'ear discsli'e relatively far apart in radial direction, which necessitatesa very heavy connectionfan'd displacing construction for the set' of friction wheels and makes the controlby a governor impossible. The invention nowi aim's'at providing a variable speed friction gear of the kind described "above, which can be "easily" controlled with very little forces, more particularly directly by a" governor wfhout declutcliing the friction wheels'from' the main gear discs.

To this purpose according to the invention in the first place the'friction wheels are mutually coupled r r'rqtam'on "in opposite sense. In this way the possibility is obtained, under maintenance of thecompensationof forces which prevents tipping of ltliesje't of friction Wheels between the main'g r discs, to use'srnall friction wheels, the spindle: of wh'icli standing perpendicular to the'directionof the two 1mm gear spindles or making asharp angle 'with the surfaces of the main -gear discs and standing in the direction of wherebya'ininirnii niof n rest obtained.

' Simpleaii'd appropriateconstructions can be then stand perpndicular'to the disc "surfaces,

the eby l theses-1 its tim re ease furthermore jean" appropriately of the set of friction wheels can easily be mastered and a relatively light and easily controllable control mechanism can be used.

Using the above me'ntioned favourable circumstances, further according to the inventio'm for attaining the aimed purpose, the set of friction wheels is fixed'to a housing, whichis hanged between the two main gear discs swingingly in the Y direction of displacement of theset'of friction whels,"on a control rod, which uses is m' umed displaceably in its axial direction. In this way it will be'obtained that on displacing the ffiction wheels no friction has to be' overcome, as a displacement of the control rod in'one direction or one other, only'that the housing withfthe'friction 'wl'ieelsis somewhat tipped outw'ar dfor inward, after which the friction wheels will roll outward respectively inward on the main gear discs," in consequence of the rotation of these discs, until the housing stands again perpendicularly under the pointof suspension on the control rod. This construction is particularly adapted'for use of a governor control and'ca'n also be used for high capacity gears.

For preventing undesired swinging movements, the housing with the set of friction wheels 'i's'appropriately connected to the control rod in'a restrictedly swinging manner;

A very simple and efficient construction can be obtained if the friction wheels are made running 'directlyagainst oneanother and areconnected to the housing with "at least one hinged'arm. The friction wheels are then always automatically pressed against one another and against the main gear discs with the same pressure as the coupling pressure exercised on the inain gear discs, so that wear has no influence on the wink; ing ofthe gear. l

Further according to the invention, the friction Wheels canbe coupled with one another withth'e aid'of a transmission, eventually with one or more intermediate spindles. The transmission, c n s s a na wheel transmission. In such a construction the tooth wheelscan be of equal or unequal diameter, so that, besides a simple transmission with opposite sense of rotation, at the sametirne also as desired or as wanted, by choice of the transmission ratio, a multiplication or, reduction gear can be obtained. As theusual governors, more particularly centrifugal governors, have generally a square characteristic curve, whereas for many 'applicat s of a gear according to the invention a linear or othershaped characteristic curve of the gQYs ernor will be necessary, the gear according to the invention can be provided with means for correcting the characteristic curve, more particularly, by that the control rod which is connected with the governor, cooperates with a system of adjustable return springs, which will be brought into action after one another when the control rod is displaced from the rest position. The invention will now be described with reference to the drawings, in which some more 01 less diagrammatic examples of construction are shown. In the drawing:

Fig. 1 shows a side elevation of a variable speed friction gear with a clutch coupling and governor control according to this invention,

Fig. 2 shows a top elevation of Fig. l, V

Fig. 3 shows an end view of the return means of the control rod and V Fig. 4 shows a side elevation of Fig. 3,

Fig. 5 shows a top view of another variable speed friction gear according to the invention,

Fig. 6 shows a set of friction wheels according to the invention with multiplication or reduction tooth wheel transmission,

Fig. 7 shows a set of friction wheels with tooth wheel and chain transmission and intermediate spindle,

Fig. 8 shows a side elevation of the mechanism for the manual displacement of the control rod and Figures 9, 10 and 11 show details of the limited swinging connection of the housing of the friction wheels used in the embodiment of Fig. 5.

In the drawing I and 2 ar the two rotatably mounted main gear spindles, which are mutually excentric and carry mutually parallel main gear discs 3 and 1. The disc A is in this case slidably a are secured two arms 8 and 9, which are in turn hinged to a housing It. The housing Iii possesses at the top an eye H with which it is swingingly suspended between the discs 3 and t on a control rod I2, for instance by that the control rod is locally provided with a circumferential groove of small depth, in which lie two bolts I3, which reach laterally to the inside through the ring II, which fits with some play round the control rod. The edges of the ring at the same time erve for limiting the swinging range of the-housing with the set of friction wheels.

The control i2 is displaceably mounted in its axial direction in two bearings HA and i5 and in this case it is connected at one end !6 with a cable ll, which is led over two rollers iii and I9 and fixed with the other end to a regulating by the characteristic curve of the regulation of .the whole device can be chosen as desired or as wanted. Furthermore the transverse bar .22 is adjustable on" the control rod I2"bymeans of the adjusting nut 26, whereby the rest position of the device can be adjusted.

Between the governor 2| and the main gear disc 4 furthermore a spring 21 is mounted round the spindle 2, which spring gives the coupling pressure of the variable speed gear, as well as the coupling pressure of the clutch coupling 28. The clutch coupling 28 serves for declutching the driven spindle 2 with running driving spindl and varible speed gear, which could be of interest, for instance fordriving motorcars.

In the embodiment according to Fig. 5 the driving gear spindle l and the driven gear spindle 2 are rotatably mounted in fixed bearings 39 and 3!! and each spindle carries a main gear disc 3 resp. 4. Between the two discs 3 and 4 is again arranged a set of friction wheels 6 and I. The friction wheels are mounted in a housing [0 with their spindles mutually parallel and at the same time parallel to the connecting line of the centers of the two main gear discs. The housinglfi is supported in such a mannerthat the housing can perform a limited rocking movement between the twomain gear discs. The two friction wheels 6 and l are mutually coupled for rotation in opposite sense by a set of tooth wheels 3! and 32 having the same diameter in thi case. The arrangement is constructed in such a manner, that the touching places of each of the friction wheels with each of the adjacent gear discs lie opposite in the direction of the two main gear spindles, so that tipping tendencies of the set of friction wheels are restricted to a minimum.

For the fixation to the control rod E2, the hou ing it? possesses at the top a transverse rib (Fig. 10) with an eye Ii. This eye fits round a ball shaped member 34 (Fig. 9) of the control rod i2 and is maintained on, this member by means of two hollowed rings 35 and 3? (Figll), which are secured to the rib 33 on both sides of the eye I]. For limiting the rocking or swinging movements of this fixation round the ball and socket joint, furthermorea pair of shields 31 and 38 are fixed to the rib 33, lying laterally against the sidewalls of the control rod !2, which has a square cross section on both sides of the ball 34, and embracing the control rod with some play at the ;upper and bottom side of it. In consequence the housing It! can practically only swing in the plane through the control rod and the center line of the housing, and yet only so far as the end'walls of the shields 3'8 and 38, which are bent inward, will tolerate the movement. The control rod i2 is mounted slidably in'its axialdirection in the middle over the two main gear discs'3' and 4 in bearings l4 and i5. When the rod'is displaced in one direction or the other, the jhousing iii with the friction wheels Band 1 will be tipped or rocked, which will cause; when the variable speed gear is turning, that the friction wheels 6 and 7 will roll in the direction in which the housing is tipped over the main geardiscs, and therefore will move outward or inward, until they stand again vertically under the point of suspension of the housing I0. These displacements'therefore necessitate no large forces, while also no wear arises. In consequence this construction is very suitable for automatic control by means of a governor. g V V In the shown embodiment a centrifugal governor 2| is used with a regulating lever 20, which is connected with one end I6 of the control rod I2 by means of a cable I! running over guide pulleys l9 and 18. For the return movement the control rod l2'is provided at the other end with page? a spring 39. which presses a ains th bear n 14 on one hand and against theiringlll with adjusting nut 26 on the other hand. The coupling pressure for the variable speed friction gear is obtained by the spring. 21, which presses the main gear disc 4, which is slidably mounted on the gear spindle 2 with the boss 5, in the direction of the disc 3. If desired, this coupling pressure can be augmented with increasingloadsby a coupling with .inclined surfaces in the boss 5. The coupling pressure for the clutch coupling 28 is delivered'by'th' se'c'ond coupling spring 27a. For enabling a reversing of thesense of rotation of the driven spindle;2,, if desired,,for instance for vehicles which must also, be able to ride backwardy thecontrol 'rod "1 2' is displacea-ble by hand in such a:manner that the..housing I 0 with the friction wheels 6 and I. passes to the other. sidev of, the center of the disc 3. For this purpose, 'throd lzis'provided with a lateralprojection 4| which cooperates with a slot 42 of the hand lever 43, turning round the center "it of a disc segment with teeth at, in respect of which the lever can be displaced and fixed.

As it is impossible, or in any way not advisable, to displace the set of friction wheels beyond the center of the driVing disc during running of the gear discs, for changing over from forward to backward drive or inverse, declutching of the friction wheels can take place, for instance by means of a rocking lever, which is hingedly fixed at one end to the frame or gear housing and can be pressed with an intermediate point against a ball or pivot in the center of the disc 4 by manual actuation of the other end. In this way the disc 4 can be pressed away from the disc 3, against the action of the coupling spring 21, whereby the housing H] with the friction Wheels hangs released and free from the two main gear discs 3 and 4 and can easily .be brought beyond the center of the driving disc.

Fig. 6 shows diagrammatically a same set of friction wheels as used in the device according to Fig. 5, however with the difference that the tooth wheels 3| and 32, with which the two friction wheels are mutually coupled, are of unequal diameter, so that at the same time the set of friction wheels, dependent on the side where the driving disc is arranged, will act as a multiplication or reduction gear.

In Fig. 7 finally a further set of friction wheels is diagrammatically shown of which the friction wheels 6 and l are coupled for rotation in opposite sense over an intermediate spindle ill with a tooth wheel and a chain transmission. Instead of the chain transmission also a second tooth wheel transmission with a second intermediate spindle can be used. In this way, if necessary, still larger transmission ratios can be obtained between the two friction wheels.

In the embodiments according to the Figures 6 and '7, in which the circumferential speed of the two friction wheels 3| and 32 is mutually different, it has to be taken into account that when the housing H3 is rocked or tipped by displacement of the control rod [2, the displacements of the two friction wheels on the main gear discs will become unequal. Therefore the slower friction wheel can appropriately be separately suspended on an arm which is flexible with respect to the housing in a direction parallel to the surfaces of the two main gear discs. The lagging friction wheel then automatically comes in a more slanting position with respect to the two main gear discs, so that it can follow the other ,friction wheel. Furthermore in Fig. -'7 also a pulley transmission can be used instead of a chain transmission.

I ,driven spindle also a reversing gear, for instance with beveled tooth wheels can be used. Furthermore, instead of a centrifugal governor, an electromagnetic or other electrical governor can be applied, for instance consisting of a dynamo drivenrby one of the main gear spindles, which delivers current to a coil in the prolongation of the control rod l2, whereby this latter, will be sucked more or less into the coil in proportion to the number of revolutions to be controlled and thus displaces the control rod in the necessary degree and direction.

Finally, the clutch coupling 23 and the governor 25 with the parts belonging to it, do not belong to the proper variable speed friction gear and therefore can also be omitted. The end it of the control rod E2 is than connected with a displacing and locking mechanism for attendance by hand.

What I claim is:

1. A variable speed friction gear including in combination, a main rotatably mounted drive spindle, a rotatably mounted driven spindle arranged parallel to the axis of the drive spindle and eccentrically thereof, main gear discs connected to and extending transversely of the adjacent ends of said spindles and positioned in opposed spaced relation with respect to each other, a longitudinally shiftable control rod mounted in spaced relation to the spaced discs and extending transversely of the axes of the spindles, a housing swingably connected to the control rod and positioned perpendicularly of the axis of the spindles and including a portion extending between the discs, friction wheels rotatably mounted with respect to the housing connected to said portion and coupled to each other for rotation in opposite directions and also frictionaliy engageable respectively and cooperating with the adjacent main gear discs, and means for axially displacing the control rod with the housing and friction Wheels thereon.

2. A variable speed friction gear including in combination, a main rotatably mounted drive spindle, a rotatably mounted driven spindle arranged in the same horizontal plane of the drive spindle but eccentrically thereof, main gear discs connected to the adjacent ends of said spindles and positioned in opposed spaced relation with respect to each other, a longitudinally shiftable control rod arranged above the spaced discs and transversely of the axes of the spindles, a housing swingably suspended from the control rod and positioned perpendicularly of the axes of the spindles and between the discs, friction wheels rotatably mounted with respect to the housing and coupled to each other for rotation in opposite directions and also frictionally engageable respectively and cooperating with the adjacent main gear discs, and means for axially displacing the control rod with the housing arid friction wheels thereon.

'and arms hingedly suspended from the casing for rotatably supporting the friction wheels.

5. A variable speed friction gear as claimed in claim 1 in which the driven spindle includes two laligning sections, a clutch coupling between said sections, the main friction gear being slidabiy and Vyieldably mounted on one of said sections, a centrifugal governor on the other of the driven spindle sections and wherein the means for axial- 1y displacing the control rod includes a regulat- 2 ing lever 'operatively connected with the governor, flexible connecting means between one end of the regulating lever and one end of the control rod for displacing the control rod in one direcfloated means jassociated'with the other end oj th' control' rod for. displacing the control rod in the opposite direction.

' 6 ."A variable speed friction gear according to 5 claim 5 i'nwhich the-me'ans associated with the other end of the control rod includes an abutment member on the control rod and a series of ad- 'justable' I return springs cooperating with the abutment.

10 JAc oBus 'JOANNES VAN LEEUWEN.

"REFERENCES CITED The following references are of record in the ffileof this patent:

15 UNITED STATES PATENTS Number Name Date 777363 Christie Dec. 20, 1904 0 V. FOREIGN PATENTS Number Country Date 4,613 Great Britain Feb. 24, 1906 667,323 France June 10, 1929 

